This invention relates to new and useful improvements in a ventilation system for the crankcase of an internal combustion engine.
1. Field of the Invention
Blow-by gases and vapors, such as moisture in the form of steam, hydrocarbons, and unburned fuel, enter the crankcase lubricating oil chamber during IC. engine operation, the gases and vapors occuring because of leakages past the piston rings during operation cycles.
If not removed as fast as they are introduced into the crankcase, contamination of the lubrication oil ensues. This condition has existed since the first IC engine was put into service.
Lubricants are formulated with an additive package for the purpose of suspending and emulsifying extraneous particles picked up from the atmosphere and blow-by vapors, plus gums, varnishes, tars, and acids generated by the combustion process.
Ventilating or scavenging crankcase systems in the past have attempted to provide a method for removing these undesirable particles into the atmosphere by a pressure method.
In normal operation of a reciprocating I.C. engine there is a certain amount of crankcase vapors, continually being developed. These consist in part of gaseous combustion products entering the crankcase by passing between the piston rings and cylinder walls, valve guides and valve stems. This particular portion of the crankcase vapors is often referred to as blow-by.
The crankcase vapors are normally comprised of, fuel, moisture hydrocarbons, soot combustible materials such as atomized oil, diesel fuel, and heavy particulate resulting from engine operation.
The releasing of such vapors and gases into ambient atmosphere is directly related to the development of a smog atmosphere. Obviously, the development of a means for reducing air pollution due to engine operation is a desideratum.
2. Description of the Prior Art
Numerous devices are known to the prior art which function to remove crankcase vapors and the like from the crankcase and pass same into the air carburetor and filtering system or intake manifold thereof unfiltered. For the most part, these crankcase vapors handling devices use a pushing or self-developed pressure method to release the vapors from the crankcase into the intake manifold without filtering or treating same, which my system does.
Thus, by so doing impregnating the lubricant with contaminates is eliminated, oil usage is prolonged, and less consumption is accomplished.
Some systems have been provided by establishing communication between the crankcase interior and the vacuum process now existing in the engine intake manifold. These systems, however, are plagued with the problem of adequate volumetric control of the undesirable vapors, solids and so on, under all conditions of the engine operation.
An apparatus for treating crankcase vapors is now known of which provides for directly removing the crankcase vapors from the crankcase into the intake manifold of the engine. While it removes the crankcase vapors from the engine, it does not substantially increase the hydrocarbon exhaust pollution due to the crankcase vapors being passed through the engine combustion system because of a depth packed filtering processing system before being introduced to the atmosphere.
Another known apparatus utilizes an indirect exhaust manifold heat exchanger to warm the vapors before they are introduced into the engine intake. Such a heat exchanger is known in the prior art as having a low efficiency which only slightly warms the vapors before they are introduced into the engine. The process of warming crankcase vapors and introducing them directly into the engine intake does not make them more significantly suitable for combustion to pollute the atmosphere.
With a gas engine running at idling speed and minimum load conditions, the throttle valve of the carburetor is substantially closed and hence, develops a maximum vacuum downstream of the throttle valve. During such a phase of engine operation, there is a minimum of leakage of gases, vapors and solids into the crankcase chamber. Like the prior application, a diesel engine has little vacuum in the intake air system at idle, this being the necessity of the compressor in constant use as is the operation of the evaculator system.
This constantly keeps the presence of moisture and diesel vapors in the crankcase at a negative state, which in turn minimizes the dilution of the lubricant and significantly reduces oil consumption previously being pushed out of the breather tube in the form of vapors, and at the same time eliminating back pressure to the underside of the pistons, stabilizing the overall performance of the engine. One half pound PSI of constant crankcase back pressure is equal to 86# of drag at all the running time of engine.
In a gas application with the throttle moved to a loaded or more fully-opened position, the manifold vacuum pressure approaches atmosphere effective conditions. At the same time the amount of blow-by gases, vapors and solids emitted into the crankcase and related chambers is substantially increased.
Ergo the need for an efficient crankcase evaculating system capable of constantly: 1. volumetrically controlling the vacuum of the crankcase back pressure, 2. versus ambient atmospheric pressure, 3. intake manifold vacuum and 4. blown air pressure.
In the case of turbo-powered diesel engine power plants, when the engine is under full load the blower is pressurizing the air into the intake manifold. This is the substantial explanation of the difference between this process hereof and the known prior art--#1 In order to remove the so-called fumes from the crankcase ; #2 filtering them to a cleaner state of condition than originally used; #3 the compressor as is adopted in this process is to accommodate three requirements at the same time,that being:
1. evacuating the fumes from the crankcase
2. drawing them through an effective depth-type filtering system and
3. exceeding the air pressure that is being exerted in the intake manifold by the engine blower.
If such a condition is not maintained constantly, a back lash will take place on the evaculator process, that is why the metered pressure from the compressor into the intake manifold has to exceed that of the blower of the engine at all times, supplying additional air and clean atomized fuel to generate additional horse power.
The embodiment of the crankcase fumes treatment apparatus of the present invention envisions a dynamic depth-type filtering system which cleans fuel vapors, and moisture, also non-ferrous solids from the engine crankcase blow-by. The solids are trapped by the filter element which prevents them from reentry to the engine intake manifold in contrast to prior art 2. However, the fuel vapors contained in the blow-by are cleaned and reused by the engine to general horsepower. By extracting the solid contaminants, porous and nonporous particulate but reintroducing cleaned diesel vapors to engine, wear is reduced, horsepower is increased, and the useful life of crankcase lubricant is prolonged and consumption is reduced. Returning fuel vapors to the engine intake manifold increases engine horsepower performance and fuel efficiency dramatically.
The invention provides a crankcase fumes treatment apparatus having a crankcase vapors and solids trap communicably connected with an I.C. engine between the crankcase and the intake manifold which in use will pass the resulting vapors into the intake manifold of the connected engine.
The system offers suitable application in diesel-driven trucks, tractors and buses, diesel-driven marine vessels and industrial generators of all types. Such a system can be modified to work very satisfactorily on automotive applications.